Medicaid and CHIP: 85,614,581 people enrolled [1]
Military: 9.5 million people covered [2]
The US has not one but two of the largest single payer health insurance programs in the world.
Medicare alone has more people enrolled than any European country's single payer programs other than Germany (pop 83,294,633) and the UK (pop 67,736,802).
[0] https://medicareadvocacy.org/medicare-enrollment-numbers/ [1] https://www.medicaid.gov/medicaid/program-information/medica... [2] https://www.health.mil/Military-Health-Topics/MHS-Toolkits/M...
As they said, it is bizarre the lengths the US will go to to maintain its layered system. It seems purpose built to screw people over.
If you have an example of a country with a single program that has more effective outcomes for a population of similar makeup and size, that would be a useful comparison.